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Multi-scale modelling of ice-structure interactions
Get PDFThe present investigation has been devoted to the modeling of the ice-structure interactions by using the state-of-the-art technique, peridynamics. Peridynamics is a new continuum mechanics formulation originally developed at Sandia National Laboratories, USA and very suitable for failure analysis of structures due to its mathematical structure. Structures can vary from thin-walled structures such as ship hulls or airplane fuselage to bridges and wind-turbines. Furthermore by using peridynamics structural failure can be observed as compressive, tensile, bending or buckling failure and materials can be classified as elastic, viscoelastic or plastic.;Peridynamic equation is in integro-differential equation form rather than a partial differential equation as in the classical continuum mechanics which allows the continuous usage of these equations without specially treating the discontinuities. Although relatively new, it is successfully verified and utilized for modelling both metallic and composite structures. Hence, it is an excellent candidate to investigate complex problems such as the ice-structure interaction modelling. Furthermore, in a general sense, it may bring a new dimension to the analysis of marine structures especially in the area of arctic engineering.;Furthermore, peridynamic solver was developed including 2D and 3D geometry definitions together with peridynamic mesh. Several different solvers were implemented, such as explicit solver, adaptive dynamic relaxation and direct solver. In order to reduce the computational time, several family search algorithms (such as brute-force search, region partitioning algorithm, K-d tree and R-tree algorithms) were tested and implemented together with parallelization of most time consuming parts of code. Finally, several numerical studies were considered in order to demonstrate ice-structure interaction via peridynamic analysis.;Where those numerical studies range from 2D and 3D Bond Based peridynamic models used for analysis of ice splitting loads for in-plane failure and impact analysis between cylindrical (offshore structures) and conical (ship's bow) rigid bodies and ice sheet. Furthermore advanced peridynamic model for Mindlin plate resting on Winkler foundation was developed in order to test for out-of-plane failure of an ice sheet.The present investigation has been devoted to the modeling of the ice-structure interactions by using the state-of-the-art technique, peridynamics. Peridynamics is a new continuum mechanics formulation originally developed at Sandia National Laboratories, USA and very suitable for failure analysis of structures due to its mathematical structure. Structures can vary from thin-walled structures such as ship hulls or airplane fuselage to bridges and wind-turbines. Furthermore by using peridynamics structural failure can be observed as compressive, tensile, bending or buckling failure and materials can be classified as elastic, viscoelastic or plastic.;Peridynamic equation is in integro-differential equation form rather than a partial differential equation as in the classical continuum mechanics which allows the continuous usage of these equations without specially treating the discontinuities. Although relatively new, it is successfully verified and utilized for modelling both metallic and composite structures. Hence, it is an excellent candidate to investigate complex problems such as the ice-structure interaction modelling. Furthermore, in a general sense, it may bring a new dimension to the analysis of marine structures especially in the area of arctic engineering.;Furthermore, peridynamic solver was developed including 2D and 3D geometry definitions together with peridynamic mesh. Several different solvers were implemented, such as explicit solver, adaptive dynamic relaxation and direct solver. In order to reduce the computational time, several family search algorithms (such as brute-force search, region partitioning algorithm, K-d tree and R-tree algorithms) were tested and implemented together with parallelization of most time consuming parts of code. Finally, several numerical studies were considered in order to demonstrate ice-structure interaction via peridynamic analysis.;Where those numerical studies range from 2D and 3D Bond Based peridynamic models used for analysis of ice splitting loads for in-plane failure and impact analysis between cylindrical (offshore structures) and conical (ship's bow) rigid bodies and ice sheet. Furthermore advanced peridynamic model for Mindlin plate resting on Winkler foundation was developed in order to test for out-of-plane failure of an ice sheet
Developing chemical tools for the cancer kinome, targeting DYRK2 in triple negative breast cancer
No full textThis thesis was previously held under moratorium from 31/03/2021 until 31/03/2024. Access to the digital copy is restricted to Strathclyde users until 31/03/2026
Anti-oppressive practice in social work education, and black African mothers' lived experiences of raising children on the autism spectrum in Scotland
Get PDFThis thesis was previously held under moratorium from 27th January 2021 until 27th January 2023.This doctoral research aims to develop an understanding of social workers’ interactions with Black and Minority Ethnic (BME) families in Scotland. This is achieved through considering the concept of anti-oppressive practices within social work education; within the experiences of social worker to BME community interactions in the field; and the experiences of Black African mothers raising children on the autism spectrum in Scotland. Anti-oppressive practice is a concept used to frame and understand oppression in operation at various levels in society. Proponents of anti-oppressive practice argue that it is advantageous because it bisects various identity markers (Dominelli, 2002). Additionally, BME experiences of social services is sparse within the Scottish context (Valenti, 2017). The ethnic diversity in Scotland is predicted to increase (Walsh, 2017), so investigation into BME experiences is essential. The focus on African mothers is relevant in recognising inter community differences rather than amalgamating their experiences into a homogeneous ‘BME’ experience. This qualitative research is philosophically underpinned by descriptive phenomenology. The lived experiences of 6 social work educators, 10 students, 6 social workers, and 4 Black African mothers raising children on the autism spectrum were captured. The data was collected through interviews, a focus group session, written responses, and documentary evidence. The data was explicated using Hycner’s simplified (1999) process in descriptive phenomenology. The findings reveal the coupling of the workers’ education and training; their lived experiences; and the changes in societal demands shape their understanding of anti-oppressive practice. The findings provide a layer of insight into discord in perceived social work roles, and expectations by Black African mothers of those roles in reality. The research contributes to the sparse research landscape in Scotland through exploring the experiences of Black African mothers as a subgroup of BME communities. Therefore, these findings have wider implications for anti-oppressive social work practice with wider BME communities in Scotland.This doctoral research aims to develop an understanding of social workers’ interactions with Black and Minority Ethnic (BME) families in Scotland. This is achieved through considering the concept of anti-oppressive practices within social work education; within the experiences of social worker to BME community interactions in the field; and the experiences of Black African mothers raising children on the autism spectrum in Scotland. Anti-oppressive practice is a concept used to frame and understand oppression in operation at various levels in society. Proponents of anti-oppressive practice argue that it is advantageous because it bisects various identity markers (Dominelli, 2002). Additionally, BME experiences of social services is sparse within the Scottish context (Valenti, 2017). The ethnic diversity in Scotland is predicted to increase (Walsh, 2017), so investigation into BME experiences is essential. The focus on African mothers is relevant in recognising inter community differences rather than amalgamating their experiences into a homogeneous ‘BME’ experience. This qualitative research is philosophically underpinned by descriptive phenomenology. The lived experiences of 6 social work educators, 10 students, 6 social workers, and 4 Black African mothers raising children on the autism spectrum were captured. The data was collected through interviews, a focus group session, written responses, and documentary evidence. The data was explicated using Hycner’s simplified (1999) process in descriptive phenomenology. The findings reveal the coupling of the workers’ education and training; their lived experiences; and the changes in societal demands shape their understanding of anti-oppressive practice. The findings provide a layer of insight into discord in perceived social work roles, and expectations by Black African mothers of those roles in reality. The research contributes to the sparse research landscape in Scotland through exploring the experiences of Black African mothers as a subgroup of BME communities. Therefore, these findings have wider implications for anti-oppressive social work practice with wider BME communities in Scotland
Privatisation and public access to information in the united Kingdom
Get PDFThis thesis examines the relationship between privatisation and public access to official information in the United Kingdom. Through a combination of theoretical and empirical analysis, it addresses two main questions: (1) How does privatisation, broadly defined to include outsourcing, affect information access under freedom of information legislation (FOI) and the Environmental Information Regulations 2004 (EIR)? (2) If privatisation negatively affects access to information, then which legal mechanisms are most effective in preserving information rights?;The research is grounded in a theoretical framework that considers the historical development and conceptual underpinnings of open government and access to information (ATI) legislation within the UK. This framework provides the context for two case studies and sets out a democratic-expansive vision for extending ATI obligations to private bodies delivering public services or performing 'functions of a public nature'. To that end, the thesis is situated within the wider scholarly literature on the public-private distinction in administrative law.;The two case studies focus on the water industry within the UK and the free schools programme in England. These empirical investigations demonstrate the different ways in which different forms of privatisation affect information access. Through a combination of stakeholder interviews, FOI/EIR requests, and doctrinal analysis, the findings of the case studies indicate that privatisation affects both the scope and the operation of the ATI legislation. The thesis concludes, based on the normative claim that information rights should be preserved in privatised public services, that both legislative reform and amendment to the UK's ATI laws are needed.This thesis examines the relationship between privatisation and public access to official information in the United Kingdom. Through a combination of theoretical and empirical analysis, it addresses two main questions: (1) How does privatisation, broadly defined to include outsourcing, affect information access under freedom of information legislation (FOI) and the Environmental Information Regulations 2004 (EIR)? (2) If privatisation negatively affects access to information, then which legal mechanisms are most effective in preserving information rights?;The research is grounded in a theoretical framework that considers the historical development and conceptual underpinnings of open government and access to information (ATI) legislation within the UK. This framework provides the context for two case studies and sets out a democratic-expansive vision for extending ATI obligations to private bodies delivering public services or performing 'functions of a public nature'. To that end, the thesis is situated within the wider scholarly literature on the public-private distinction in administrative law.;The two case studies focus on the water industry within the UK and the free schools programme in England. These empirical investigations demonstrate the different ways in which different forms of privatisation affect information access. Through a combination of stakeholder interviews, FOI/EIR requests, and doctrinal analysis, the findings of the case studies indicate that privatisation affects both the scope and the operation of the ATI legislation. The thesis concludes, based on the normative claim that information rights should be preserved in privatised public services, that both legislative reform and amendment to the UK's ATI laws are needed
Econometric modelling in a changing, globalised world
Get PDFThis thesis takes the literature on multi-country Bayesian Panel Vector Autoregressions as its starting point. In three self-contained but related essays, we refine and apply the econometric methods and modelling assumptions necessary to objectively consider different aspects of globalisation. The first essay analyses the Asia Pacific's possible decoupling from the US. We use Bayesian variable selection methods to model empirically relevant interdependencies between the US and eleven Asia Pacific countries. This allows us to capture regional interdependencies and bidirectional spillovers between the US and Asia Pacific. We show that shocks to US economic conditions, financial markets and uncertainty are important but regional shocks play a larger role in a typical Asia Pacific country. We also detect substantive spillovers from the Asia Pacific to US financial markets.;The second essay devises a novel econometric strategy to distinguish between: interdependence, contagion through interdependence and abrupt contagion. Appealing to multiple definitions of contagion, we allow the nature and magnitude of interdependencies and transmission channels selected for inclusion to changeover time. Using our approach, we analyse crisis episodes in Latin America. We only detect abrupt contagion during the global financial crisis from the US to Argentina and Brazil. During crises, results also show that macroeconomic and uncertainty channels play a role not just financial channels. The third essay uses professional forecast data to analyse spillovers in five components of uncertainty across advanced and emerging economies. Uncertainty surrounding output growth, inflation, the interest rate, exchange rate and current account is considered. While the US affects other economies through interest rate, exchange rate and current account uncertainty, interest rate and inflation uncertainty spillovers are also seen from the Eurozone and UK. Uncertainty spillovers are more frequently observed, but smaller when forecaster disagreement rather than the variance of mean forecast errors is used to proxy uncertainty.This thesis takes the literature on multi-country Bayesian Panel Vector Autoregressions as its starting point. In three self-contained but related essays, we refine and apply the econometric methods and modelling assumptions necessary to objectively consider different aspects of globalisation. The first essay analyses the Asia Pacific's possible decoupling from the US. We use Bayesian variable selection methods to model empirically relevant interdependencies between the US and eleven Asia Pacific countries. This allows us to capture regional interdependencies and bidirectional spillovers between the US and Asia Pacific. We show that shocks to US economic conditions, financial markets and uncertainty are important but regional shocks play a larger role in a typical Asia Pacific country. We also detect substantive spillovers from the Asia Pacific to US financial markets.;The second essay devises a novel econometric strategy to distinguish between: interdependence, contagion through interdependence and abrupt contagion. Appealing to multiple definitions of contagion, we allow the nature and magnitude of interdependencies and transmission channels selected for inclusion to changeover time. Using our approach, we analyse crisis episodes in Latin America. We only detect abrupt contagion during the global financial crisis from the US to Argentina and Brazil. During crises, results also show that macroeconomic and uncertainty channels play a role not just financial channels. The third essay uses professional forecast data to analyse spillovers in five components of uncertainty across advanced and emerging economies. Uncertainty surrounding output growth, inflation, the interest rate, exchange rate and current account is considered. While the US affects other economies through interest rate, exchange rate and current account uncertainty, interest rate and inflation uncertainty spillovers are also seen from the Eurozone and UK. Uncertainty spillovers are more frequently observed, but smaller when forecaster disagreement rather than the variance of mean forecast errors is used to proxy uncertainty
The wild west in Italy and in the Italian Imagination, travel writing, Buffalo Bill's Wild West Show and popular culture
No full textStrathclyde theses - ask staff. Thesis no. : T1579
A novel device for interrogation of neuron connectivity in acute brain slices
Get PDFThe complexity and scale of inter-neuron communication in the human brain presents an immense obstacle to understanding the mechanisms of information processing and how changes to neuronal connectivity are associated with pathological states. Neuron interactions underlie functional roles of local brain networks, for instance memory and cognitive abilities, which are often detrimentally impacted in cognitive states. Therefore, elucidating connectivity in the brain, between numerous subtypes of cell and in different functional regions, can provide a physiological model of appropriate neuronal behaviour. This could potentially be used to identify neuronal behaviours indicative of pathological states such as Alzheimer's disease.;Advancements in imaging technologies, such as calcium imaging and fMRI, have greatly enhanced studies of neuronal networks. However, the temporal and spatial resolution of these methods are limited in precisely determining activity observed across hundreds of neurons simultaneously. Similarly, patch clamping techniques have provided a wealth of knowledge in terms of ion channels and single-cell responses, yet are not currently operable across hundreds of neurons simultaneously.;Presented here is a novel microelectrode array (MEA) with high spatial resolution (60 μm electrode pitch) combined with a data acquisition setup capable of sampling electrical signals at a frequency of 20 kHz, enabling precise recording of neuronal activity in acute rat brain slices. Electrode tips were exposed at the tips of silicon needles designed to bypass cellular damage resulting from tissue preparation to record from viable neurons. The device demonstrated a signal-to-noise ratio of 10:1 in the presence of tissue and platinised electrode impedances of 200 kΩ, which are appropriate electrical characteristics with which to perform extracellular electrophysiological recordings.;The device was integrated into a custom data acquisition system and, through a robust spike sorting process, successfully identified individual neurons. Neuronal signals were then assessed for temporal and amplitude features to discriminate subtypes of neurons to indicate functional roles within the network. This data was then used to develop several approaches to connectivity analysis afforded by the resolution of the device. Finally, the effectiveness of the needles in bypassing damaged tissue was evaluated histologically. These findings suggested that the preparation used here resulted in extensive cellular damage at the section surface. However, these results indicate potential for this approach to study of neuronal connectivity across hundreds of viable neurons.The complexity and scale of inter-neuron communication in the human brain presents an immense obstacle to understanding the mechanisms of information processing and how changes to neuronal connectivity are associated with pathological states. Neuron interactions underlie functional roles of local brain networks, for instance memory and cognitive abilities, which are often detrimentally impacted in cognitive states. Therefore, elucidating connectivity in the brain, between numerous subtypes of cell and in different functional regions, can provide a physiological model of appropriate neuronal behaviour. This could potentially be used to identify neuronal behaviours indicative of pathological states such as Alzheimer's disease.;Advancements in imaging technologies, such as calcium imaging and fMRI, have greatly enhanced studies of neuronal networks. However, the temporal and spatial resolution of these methods are limited in precisely determining activity observed across hundreds of neurons simultaneously. Similarly, patch clamping techniques have provided a wealth of knowledge in terms of ion channels and single-cell responses, yet are not currently operable across hundreds of neurons simultaneously.;Presented here is a novel microelectrode array (MEA) with high spatial resolution (60 μm electrode pitch) combined with a data acquisition setup capable of sampling electrical signals at a frequency of 20 kHz, enabling precise recording of neuronal activity in acute rat brain slices. Electrode tips were exposed at the tips of silicon needles designed to bypass cellular damage resulting from tissue preparation to record from viable neurons. The device demonstrated a signal-to-noise ratio of 10:1 in the presence of tissue and platinised electrode impedances of 200 kΩ, which are appropriate electrical characteristics with which to perform extracellular electrophysiological recordings.;The device was integrated into a custom data acquisition system and, through a robust spike sorting process, successfully identified individual neurons. Neuronal signals were then assessed for temporal and amplitude features to discriminate subtypes of neurons to indicate functional roles within the network. This data was then used to develop several approaches to connectivity analysis afforded by the resolution of the device. Finally, the effectiveness of the needles in bypassing damaged tissue was evaluated histologically. These findings suggested that the preparation used here resulted in extensive cellular damage at the section surface. However, these results indicate potential for this approach to study of neuronal connectivity across hundreds of viable neurons
Peridynamic modeling of fire damage in composites
No full textThe predictions of composite materials responses in fire environments are important in terms of safety. This reality problem can be simplified as a thermal fluid-structure interaction problem in terms of mathematical modelling. The thermo-fluid model is used to simplify the physical properties of fire. The classical continuum mechanics has difficulty in predicting crack propagations because of the singularities of differential equations at discontinuities. Therefore, the peridynamic theory which uses the integral governing equations is a good choice to predict the damage in composite materials. It will bring convenience to simulate the composite response in fire environments using a monolithic methodology. Consequently, in the current study, both thermo-fluid modelling for fire and thermomechanical damage modelling in composites are simulated by using peridynamic theory. Therefore, the following models are developed step by step to achieve the final target.;Firstly, a fully coupled thermomechanical ordinary state-based peridynamic model is developed for isotropic materials. Both the deformation effect on the temperature field and the temperature effect on deformation are taken into consideration. Then the fully coupled ordinary state-based peridynamic model for isotropic materials is extended to laminated composites. Besides, a bond-based peridynamic laminate model was applied to predict the responses of a 13-ply composite under a pressure shock loading. Secondly, regarding the fluid model to represent fire, a peridynamic model is developed for Newtonian single-phase fluid low Reynold's number laminar flow. The high temperature should also be considered which is one of the typical properties of fire. Therefore, the heat transfer is incorporated into the fluid model to represent the thermal properties of fire. Based on the single-phase fluid peridynamic model, peridynamic model for multi-phase fluid flows is also developed.;The Navier-Stokes equations including the surface tension forces are reformulated into their integral forms. Thirdly, by combining the developed single-phase fluid peridynamic model and the ordinary state-based peridynamic solid model, a fluid-structure interaction model is developed for the simulation of weakly compressible viscous fluid and elastic structure interactions. Subsequently, the heat transfer is incorporated into the fluid-structure interaction model to predict the composite response under a fire scenario. The ISO temperature-time curve is utilized to present the high temperature which is induced by fire. The thermal degradation properties of the composite materials are also included in the numerical peridynamic composite model. Finally, the composite response underfire scenario is predicted.The predictions of composite materials responses in fire environments are important in terms of safety. This reality problem can be simplified as a thermal fluid-structure interaction problem in terms of mathematical modelling. The thermo-fluid model is used to simplify the physical properties of fire. The classical continuum mechanics has difficulty in predicting crack propagations because of the singularities of differential equations at discontinuities. Therefore, the peridynamic theory which uses the integral governing equations is a good choice to predict the damage in composite materials. It will bring convenience to simulate the composite response in fire environments using a monolithic methodology. Consequently, in the current study, both thermo-fluid modelling for fire and thermomechanical damage modelling in composites are simulated by using peridynamic theory. Therefore, the following models are developed step by step to achieve the final target.;Firstly, a fully coupled thermomechanical ordinary state-based peridynamic model is developed for isotropic materials. Both the deformation effect on the temperature field and the temperature effect on deformation are taken into consideration. Then the fully coupled ordinary state-based peridynamic model for isotropic materials is extended to laminated composites. Besides, a bond-based peridynamic laminate model was applied to predict the responses of a 13-ply composite under a pressure shock loading. Secondly, regarding the fluid model to represent fire, a peridynamic model is developed for Newtonian single-phase fluid low Reynold's number laminar flow. The high temperature should also be considered which is one of the typical properties of fire. Therefore, the heat transfer is incorporated into the fluid model to represent the thermal properties of fire. Based on the single-phase fluid peridynamic model, peridynamic model for multi-phase fluid flows is also developed.;The Navier-Stokes equations including the surface tension forces are reformulated into their integral forms. Thirdly, by combining the developed single-phase fluid peridynamic model and the ordinary state-based peridynamic solid model, a fluid-structure interaction model is developed for the simulation of weakly compressible viscous fluid and elastic structure interactions. Subsequently, the heat transfer is incorporated into the fluid-structure interaction model to predict the composite response under a fire scenario. The ISO temperature-time curve is utilized to present the high temperature which is induced by fire. The thermal degradation properties of the composite materials are also included in the numerical peridynamic composite model. Finally, the composite response underfire scenario is predicted
Demand side self-scheduling under dynamic pricing uncertainty
Get PDFPreviously held under moratorium from 1st July 2020 until 1st July 2024.The ever increasing integration of renewable energy sources creates a challenge
for electric network operation. Addressing the challenge called for changes in system
operation, in particular at distribution level. Demand side flexibility is one of the key
solutions proposed. Presently, customers start to actively manage their own energy
consumption. To manage the growing demand side flexibility and utilise it to benefit
grid operation, Demand Side Management (DSM) technologies are applied to manage
the consumption, assist system balancing and ensure the security of supply. Direct
Load Control (DLC) is a typical DSM technique, where demand corresponds to direct
control signals and being directly controlled by an external entity with short notice.
Under DLC, this may significantly discourage consumers to actively participate in
DLC due to distrust and perceived intrusiveness.
This thesis proposes a novel customer-centred self-scheduling concept that is
capable to overcome the distrust and perceived intrusiveness issues caused by DLC.
The self-scheduling approach encourages consumers to participate and make their own
decisions regarding when and how much they are going to consume domestic
appliances rather than remotely switched by operators /aggregators.
Consumer-centred scheduling tools (a basic and a stochastic tool) have been
developed in this research. The novelty of the developed scheduling tools is it
minimizes the expense of end-users’ energy consumption by automatically schedule
load devices, while satisfies consumer’s electricity usage preferences and their
predetermined living patterns. Moreover, the novel stochastic scheduling tool also
considered the rising uncertainty in the power system. It coordinates network/system
operators’ request and dynamic end-users energy usage behaviour, by combining long
term and short term planning into one procedure.
The developed scheduling tools are able to aid consumers to monitor the electricity
price signals intelligently, react to the network operators’ requirements, achieve
energy bill savings automatically, and satisfy consumers’ energy consumption
preferences at the same time.The ever increasing integration of renewable energy sources creates a challenge
for electric network operation. Addressing the challenge called for changes in system
operation, in particular at distribution level. Demand side flexibility is one of the key
solutions proposed. Presently, customers start to actively manage their own energy
consumption. To manage the growing demand side flexibility and utilise it to benefit
grid operation, Demand Side Management (DSM) technologies are applied to manage
the consumption, assist system balancing and ensure the security of supply. Direct
Load Control (DLC) is a typical DSM technique, where demand corresponds to direct
control signals and being directly controlled by an external entity with short notice.
Under DLC, this may significantly discourage consumers to actively participate in
DLC due to distrust and perceived intrusiveness.
This thesis proposes a novel customer-centred self-scheduling concept that is
capable to overcome the distrust and perceived intrusiveness issues caused by DLC.
The self-scheduling approach encourages consumers to participate and make their own
decisions regarding when and how much they are going to consume domestic
appliances rather than remotely switched by operators /aggregators.
Consumer-centred scheduling tools (a basic and a stochastic tool) have been
developed in this research. The novelty of the developed scheduling tools is it
minimizes the expense of end-users’ energy consumption by automatically schedule
load devices, while satisfies consumer’s electricity usage preferences and their
predetermined living patterns. Moreover, the novel stochastic scheduling tool also
considered the rising uncertainty in the power system. It coordinates network/system
operators’ request and dynamic end-users energy usage behaviour, by combining long
term and short term planning into one procedure.
The developed scheduling tools are able to aid consumers to monitor the electricity
price signals intelligently, react to the network operators’ requirements, achieve
energy bill savings automatically, and satisfy consumers’ energy consumption
preferences at the same time
Full waveform inversion of ultrasonic phased array data for the tomographic reconstruction of heterogeneous media for NDT
Get PDFWithin the ultrasonic non-destructive community the benchmark imaging algorithm assumes that the host material is homogeneous. This can lead to poor flaw detection, location, and characterisation. However, when the heterogeneous nature is accounted for within an imaging algorithm there is a significant improvement in the flaw images.;This work builds upon that work by creating a full waveform inversion framework to build a tomography method that reconstructs spatially heterogeneous wave speeds maps from simulated ultrasonic phased array data. This framework consists of: a Voronoi tessellation to spatially parametrise the wave speed map; a bespoke semi-analytical model that encompasses the data within an ultrasonic A-scan while being computationally efficient; a bespoke objective function toquantify how well the semi-analytical model compares to the observed data; and a Bayesian framework, namely the reversible jump Marko chain Monte Carlo method (rj-MCMC), to perform the tomographic reconstruction in the form of a posterior distribution. The reconstructed wave speed maps are then used in conjunction with an imaging algorithm (TFM), to provide enhanced flaw imaging. The quality of the imaged flaws are then quantified by calculating the signal-to-noise ratio, the flaw location error, and probability of detection via ROC curves.;This framework is first applied to a synthetic randomly heterogeneous material with a side drilled hole present. It is then applied to a layered medium that contains three inclusions contained in different layers. The latter case being studied extensively in different scenarios and phased array set ups. A new objective function is then proposed (a time windowed Hilbert transform) which is applied to the layered medium allowing for the comparison of different objective functions.Within the ultrasonic non-destructive community the benchmark imaging algorithm assumes that the host material is homogeneous. This can lead to poor flaw detection, location, and characterisation. However, when the heterogeneous nature is accounted for within an imaging algorithm there is a significant improvement in the flaw images.;This work builds upon that work by creating a full waveform inversion framework to build a tomography method that reconstructs spatially heterogeneous wave speeds maps from simulated ultrasonic phased array data. This framework consists of: a Voronoi tessellation to spatially parametrise the wave speed map; a bespoke semi-analytical model that encompasses the data within an ultrasonic A-scan while being computationally efficient; a bespoke objective function toquantify how well the semi-analytical model compares to the observed data; and a Bayesian framework, namely the reversible jump Marko chain Monte Carlo method (rj-MCMC), to perform the tomographic reconstruction in the form of a posterior distribution. The reconstructed wave speed maps are then used in conjunction with an imaging algorithm (TFM), to provide enhanced flaw imaging. The quality of the imaged flaws are then quantified by calculating the signal-to-noise ratio, the flaw location error, and probability of detection via ROC curves.;This framework is first applied to a synthetic randomly heterogeneous material with a side drilled hole present. It is then applied to a layered medium that contains three inclusions contained in different layers. The latter case being studied extensively in different scenarios and phased array set ups. A new objective function is then proposed (a time windowed Hilbert transform) which is applied to the layered medium allowing for the comparison of different objective functions
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